/* 全局样式重置 */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html, body {
  height: 100%;
  font-family: 'Helvetica Neue', Helvetica, 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', '微软雅黑', Arial, sans-serif;
  line-height: 1.6;
  color: #333;
  background-color: #fff;
}

/* 响应式容器 */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}

@media (max-width: 768px) {
  .container {
    padding: 0 15px;
  }
}

/* 通用按钮样式 */
.btn-primary {
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  border: none;
  color: white;
  padding: 12px 24px;
  border-radius: 6px;
  cursor: pointer;
  transition: all 0.3s ease;
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 25px rgba(102, 126, 234, 0.3);
}

/* 卡片样式 */
.card {
  background: white;
  border-radius: 12px;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
  padding: 24px;
  transition: all 0.3s ease;
}

.card:hover {
  transform: translateY(-4px);
  box-shadow: 0 8px 30px rgba(0, 0, 0, 0.15);
}

/* 标题样式 */
.section-title {
  font-size: 2.5rem;
  font-weight: 700;
  text-align: center;
  margin-bottom: 3rem;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

@media (max-width: 768px) {
  .section-title {
    font-size: 2rem;
    margin-bottom: 2rem;
  }
}

/* 动画效果 */
.fade-in {
  animation: fadeIn 0.6s ease-in-out;
}

@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* 加载动画 */
.loading {
  display: flex;
  justify-content: center;
  align-items: center;
  height: 200px;
}

/* 响应式网格 */
.grid {
  display: grid;
  gap: 2rem;
}

.grid-2 {
  grid-template-columns: repeat(2, 1fr);
}

.grid-3 {
  grid-template-columns: repeat(3, 1fr);
}

.grid-4 {
  grid-template-columns: repeat(4, 1fr);
}

@media (max-width: 1024px) {
  .grid-4 {
    grid-template-columns: repeat(2, 1fr);
  }
  .grid-3 {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 768px) {
  .grid-2,
  .grid-3,
  .grid-4 {
    grid-template-columns: 1fr;
  }
}